CN114786430B - Frequency converter cooling system device based on steelmaking waste heat and control method - Google Patents

Abstract

The invention relates to a frequency converter cooling system device based on steelmaking waste heat and a control method thereof, which are used for solving the problems of easy influence of environmental temperature, low cooling efficiency and high energy consumption in the use process of the current frequency converter; the cooling system apparatus includes: the steelmaking waste heat absorption type circulating refrigeration subsystem and the frequency converter cooling subsystem; the steelmaking waste heat absorption type circulating refrigeration subsystem comprises a waste heat end, an absorption type refrigeration unit and a heat exchange end which are sequentially connected; the frequency converter cooling subsystem comprises an electronic room and a circulating air pipeline connected with the electronic room; the circulating air pipeline comprises a return air pipeline, a cold air heat exchange pipeline and a cold air supply pipeline which are sequentially connected; the cold part of the heat exchange end is arranged in the cold air heat exchange pipeline; a heat exchange air inlet is arranged between the return air pipeline and the cold air heat exchange pipeline; a frequency converter cabinet is arranged in the electronic room, and is provided with cooling air supply equipment; the frequency converter cabinet is also provided with heat dissipation and air draft equipment.

Description

A frequency converter cooling system device and control method based on steelmaking waste heat

Technical Field

The present invention relates to the field of comprehensive application of energy-saving and low-carbon technologies in steel manufacturing, and in particular to a frequency converter cooling system device and a control method based on steelmaking waste heat.

Background Art

At present, the steel industry is a process production industry, and high-voltage inverters with energy-saving and consumption-reducing functions are widely used in the production field. At the same time, with the development of science and technology, the efficiency of high-voltage inverters can generally reach more than 95%, but due to the high power of the equipment, a large amount of heat will be continuously generated during continuous operation. Among the indicators that affect the reliability of high-voltage inverters, the ventilation, heat dissipation and dust conditions of the inverter are important parts. In the construction of an environment with low dust content of the frequency conversion equipment, timely and large-scale heat dissipation is the premise for ensuring the reliable operation of the inverter, and also the premise for reliable steel production.

Currently, there are several ways to cool high-voltage inverters, including natural cooling, forced air cooling, air conditioning cooling, and air-water circulation cooling.

For example, CN108809057A discloses a frequency converter water cooling system, which relates to the field of frequency converter technology. The system includes a frequency converter water cooling device and a frequency converter cabinet. The frequency converter water cooling device is connected to the frequency converter cabinet through an internal circulation pipeline, and an internal circulation pump source that provides power for the internal circulation pipeline. It also includes: a heat exchanger, which is connected to an external cooling water pipeline through an external circulation pipeline, and the internal circulation pipeline is partially inserted into the heat exchanger for heat exchange; a mounting base plate, which is arranged in a vertical direction, and the internal circulation pipeline, the internal circulation pump source and the heat exchanger are fixed on the mounting base plate; the height of the mounting base plate is the same as the height of the frequency converter cabinet. The frequency converter water cooling system proposed by the present invention has a frequency converter water cooling device that is adapted to the size of the frequency converter cabinet, a compact structure, convenient installation and maintenance, and high cooling performance.

CN112930075A discloses a variable frequency transmission cooling system, equipment using a frequency converter, and a cooling control method, wherein the system includes: a frequency converter cooling circuit, including a first liquid intake circuit, a first heat exchange component, and a first liquid return circuit, and heat exchange is performed with the frequency converter component through the first heat exchange component; a first control device, arranged on the first liquid intake circuit and/or the first liquid return circuit; a second control device, arranged on the first liquid return circuit; a controller assembly, electrically connected to the frequency converter component, the first control device, and the second control device. The controller assembly controls the second control device located on the second liquid return circuit and the first control device arranged on the first liquid intake circuit and/or the first liquid return circuit, thereby realizing two-stage regulation, thereby ensuring that the frequency converter works at an adapted temperature, and can also effectively adjust the pressure difference before and after the frequency converter, and solve problems such as condensation or overheating under extreme working conditions.

However, the current inverter cooling still has problems such as poor cooling effect and high dust content brought in by outside air; air conditioning cooling has the problem of high power consumption and low energy saving, and air-water circulation cooling has the problem of uneven effect due to the influence of geographical location and ambient temperature.

Summary of the invention

In view of the problems existing in the prior art, the purpose of the present invention is to provide a frequency converter cooling system device and control method based on steelmaking waste heat, so as to solve the problems existing in the current frequency converter during use, such as being easily affected by ambient temperature, having low cooling efficiency and high energy consumption.

To achieve this object, the present invention adopts the following technical solutions:

In a first aspect, the present invention provides a frequency converter cooling system device based on steelmaking waste heat, the cooling system device comprising: a steelmaking waste heat absorption cycle refrigeration subsystem and a frequency converter cooling subsystem;

The steelmaking waste heat absorption cycle refrigeration subsystem comprises a waste heat end, an absorption refrigeration unit and a heat exchange end connected in sequence;

The inverter cooling subsystem includes an electronic room and a circulating air duct connected to the electronic room;

The circulating air pipeline includes a return air pipeline, a cold air heat exchange pipeline and a cold air supply pipeline which are connected in sequence;

The cold part of the heat exchange end is arranged inside the cold air heat exchange pipeline;

A heat exchange air inlet is provided between the return air duct and the cold air heat exchange duct;

A frequency converter cabinet is arranged in the electronic room, and the frequency converter cabinet is provided with a cooling air supply device;

The inverter cabinet is also provided with heat dissipation and ventilation equipment.

The inverter cooling system device provided by the present invention realizes cooling of the inverter by using steelmaking waste heat through the adoption of a specific device design, and has the expected effects such as a wide cooling range, good cooling effect, and dust-free cooling process. At the same time, compared with other cooling systems in the field, the cooling effect is significantly improved, and the energy consumption is also significantly lower.

As a preferred technical solution of the present invention, the waste heat end includes one or a combination of at least two of the water drain, slag flushing water or flue gas hot water generated in the steelmaking process, such as a combination of water drain and slag flushing water, a combination of slag flushing water and flue gas hot water, or a combination of water drain and flue gas hot water, but is not limited to the listed values, and other values not listed within the range are equally applicable.

As a preferred technical solution of the present invention, the absorption refrigeration unit includes an absorption refrigerator, a cooling tower, a first exchanger and a second exchanger which are connected in sequence.

Preferably, the heat source inlet of the absorption refrigerator is connected to the waste heat end.

Preferably, the return water after heat exchange in the absorption refrigerator is returned to the steelmaking system through a pipeline.

As a preferred technical solution of the present invention, the cold part is arranged between the first exchanger and the second exchanger.

As a preferred technical solution of the present invention, the cold air supply pipeline is equipped with a first air supply fan.

As a preferred technical solution of the present invention, the return air duct is equipped with a first temperature detection device, a second air supply fan and a control valve in sequence along the air flow direction.

As a preferred technical solution of the present invention, the heat exchange air inlet is provided with a filtering device and a second temperature detection device.

As a preferred technical solution of the present invention, the heat dissipation and exhaust equipment is connected to the outside through an external exhaust pipe provided with a check valve.

As a preferred technical solution of the present invention, at least two inverter cabinets are provided, for example, 2, 3, 4, 5, 6 or 7, etc., but are not limited to the listed values, and other unlisted values within the range are also applicable.

In a second aspect, the present invention provides a control method for a frequency converter cooling system device based on steelmaking waste heat as described in the first aspect, the control method comprising:

The steelmaking waste heat absorption cycle refrigeration subsystem is turned on to perform refrigeration;

Obtain the appropriate operating temperature range of the inverter. If it is already in the appropriate operating temperature range, maintain it; if it does not match, determine the required cooling capacity, start the inverter cooling subsystem, and perform cooling;

During cooling or holding, compare the temperatures of the return air and the heat exchange air. If the temperature of the return air is ≥ that of the heat exchange air, turn on the heat exchange air fan to exchange heat with the cold part for cooling. If the temperature of the return air is < that of the heat exchange air, turn on the control valve to use the return air as the medium to exchange heat with the cold part for cooling.

Compared with the prior art solutions, the present invention has at least the following beneficial effects:

The inverter cooling system device and control method provided by the present invention, based on the characteristics of steelmaking enterprises, couple low-temperature waste heat resources with inverter cooling, thereby realizing the rational and efficient use of energy by steel enterprises in the dual-carbon era, while significantly improving the cooling effect of the inverter. Under the premise of achieving the same cooling effect, the energy consumption is significantly reduced compared with the existing technology, and dust-free operation of the electronic room can also be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a frequency converter cooling system device based on steelmaking waste heat in Example 1 of the present invention;

FIG2 is a schematic diagram of a circulating air duct in Example 1 of the present invention;

FIG3 is a schematic diagram of an absorption refrigeration unit in Example 1 of the present invention.

In the figure: 1-waste heat end, 2-absorption refrigeration unit, 2.1-absorption refrigerator, 2.2-cooling tower, 2.3-first exchanger, 2.4-second exchanger, 3-return air duct, 3.1-first temperature detection equipment, 3.2-control valve, 3.3-second air supply fan, 4-cold air heat exchange pipeline, 4.1-cold part, 5-cold air supply pipeline, 5.1-first air supply fan, 6-heat exchange air inlet, 6.1-second temperature detection equipment, 6.2-filter device, 7-electronic room, 7.1-exhaust pipe, 7.1.1-check valve, 7.2-inverter cabinet, 7.2.1-cooling air supply equipment.

The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

DETAILED DESCRIPTION

To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

Example 1

This embodiment provides a frequency converter cooling system device based on steelmaking waste heat, the cooling system device comprising: a steelmaking waste heat absorption cycle refrigeration subsystem and a frequency converter cooling subsystem;

The steelmaking waste heat absorption cycle refrigeration subsystem comprises a waste heat end 1, an absorption refrigeration unit 2 and a heat exchange end connected in sequence, as shown in FIG1 ;

The waste heat end 1 includes one or a combination of at least two of drain water, slag flushing water or flue gas hot water generated in the steelmaking process. Specifically, the waste heat end 1 in this embodiment uses a mixture of drain water, slag flushing water and flue gas hot water as the waste heat supply end.

The inverter cooling subsystem includes an electronic room 7 and a circulating air duct connected to the electronic room 7;

The circulating air pipeline includes a return air pipeline 3, a cold air heat exchange pipeline 4 and a cold air supply pipeline 5 which are connected in sequence, as shown in FIG2 ;

The cold part 4.1 of the heat exchange end is arranged inside the cold air heat exchange pipeline 4;

A heat exchange air inlet 6 is arranged between the return air duct 3 and the cold air heat exchange duct 4. With such a connection arrangement, when the ambient temperature is low, lower ambient air can be directly used to cool the electronic room 7, thereby maximizing the utilization of energy. In high temperature conditions, waste heat can be used for refrigeration and cooling.

The cold air supply duct 5 is equipped with a first air supply fan 5.1; the return air duct 3 is equipped with a first temperature detection device 3.1, a second air supply fan 3.3 and a control valve 3.2 in sequence along the air flow direction; the heat exchange air inlet 6 is provided with a filter device 6.2 and a second temperature detection device 6.1; by comparing the temperature in the duct with the ambient temperature, automatic control of the system can be achieved.

A frequency converter cabinet 7.2 is arranged in the electronic room 7, and a cooling air supply device 7.2.1 is arranged in the frequency converter cabinet 7.2; the cooling air supply device 7.2.1 can further deliver the cold air delivered by the cold air supply pipeline 5 to the interior of the frequency converter cabinet 7.2 to more efficiently exert the cooling effect of the cold air.

The inverter cabinet 7.2 is also provided with a heat dissipation exhaust device, which is connected to the outside through an external exhaust pipe 7.1 provided with a check valve 7.1.1. The setting of the check valve 7.1.1 can prevent the interference of external air on the cooling system, which is conducive to the long-term and efficient circulation of the cooling system.

The absorption refrigeration unit 2 comprises an absorption refrigerator 2.1, a cooling tower 2.2, a first exchanger 2.3 and a second exchanger 2.4 which are connected in sequence; the heat source inlet of the absorption refrigerator 2.1 is connected to the waste heat end 1; the return water after heat exchange in the absorption refrigerator 2.1 is returned to the steelmaking system through a pipeline; the cold part 4.1 is arranged between the first exchanger 2.3 and the second exchanger 2.4, as shown in FIG3;

At least two frequency converter cabinets 7.2 are provided. Specifically, two frequency converter cabinets 7.2 are provided in this embodiment.

Application Example 1

This application example adopts the inverter cooling system device based on steelmaking waste heat of Example 1 to cool the inverter cabinet in the central control room of steelmaking.

Specifically, it includes the following: the steelmaking waste heat absorption cycle refrigeration subsystem is turned on to perform refrigeration; at this time, the waste heat can be continuously recovered, and the cold energy generated by the conversion can be stored in the cooling tower in the system and output when needed.

Get the appropriate operating temperature range of the inverter, such as 6-8°C. If it is already in the appropriate operating temperature range, keep it. At this time, it can be maintained through internal circulation. If it does not match, determine the required cooling capacity, turn on the inverter cooling subsystem, and cool it.

During cooling or holding, compare the temperatures of the return air and the heat exchange air. If the temperature of the return air is ≥ that of the heat exchange air, turn on the heat exchange air fan to exchange heat with the cold part for cooling. If the temperature of the return air is < that of the heat exchange air, turn on the control valve to use the return air as the medium to exchange heat with the cold part for cooling.

The above control method can ensure better operation and maintenance reliability in the operation of the inverter; the efficient use of low-temperature waste heat is a favorable way to save energy and is conducive to the use of low-temperature waste heat, especially under the premise that there is no heating demand in summer. It provides a very good innovative technology that can be used and promoted, which is significantly improved compared with the existing technology. See Table 1 for details.

Table 1

By comparing the data in the table, it can be seen that the cooling system in the present invention achieves efficient cooling of the inverter while significantly reducing power consumption, and the operating cost is also significantly reduced. That is, the cooling system provided by the present invention has obvious advantages over the prior art, such as high energy efficiency and low operating cost.

It is stated that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims (6)

1. A converter cooling system device based on steelmaking waste heat, characterized in that the cooling system device comprises: the steelmaking waste heat absorption type circulating refrigeration subsystem and the frequency converter cooling subsystem;

The steelmaking waste heat absorption type circulating refrigeration subsystem comprises a waste heat end, an absorption type refrigeration unit and a heat exchange end which are sequentially connected;

The absorption refrigeration unit comprises an absorption refrigerator, a cooling tower, a first exchanger and a second exchanger which are connected in sequence;

The heat source inlet of the absorption refrigerator is connected with the waste heat end;

The frequency converter cooling subsystem comprises an electronic room and a circulating air pipeline connected with the electronic room;

The circulating air pipeline comprises a return air pipeline, a cold air heat exchange pipeline and a cold air supply pipeline which are sequentially connected;

The cold air supply pipeline is provided with a first air supply fan in a matched mode;

the return air pipeline is sequentially provided with a first temperature detection device, a second air supply fan and a control valve in a matching way along the air flowing direction;

The cold part of the heat exchange end is arranged in the cold air heat exchange pipeline;

The cold part is arranged between the first exchanger and the second exchanger;

A heat exchange air inlet is arranged between the return air pipeline and the cold air heat exchange pipeline;

The heat exchange air inlet is provided with a filtering device and second temperature detection equipment;

A frequency converter cabinet is arranged in the electronic room, and the frequency converter cabinet is provided with cooling air supply equipment;

The cooling air supply device conveys the cold air sent by the cold air supply pipeline to the interior of the frequency converter cabinet to exert the cooling effect of the cold air;

the frequency converter cabinet is also provided with heat dissipation and air draft equipment.

2. The converter cooling system apparatus based on steelmaking waste heat as claimed in claim 1, wherein said waste heat end comprises 1 or a combination of at least 2 of water drain, slag wash or flue gas heat exchange water generated during steelmaking.

3. The inverter cooling system device based on steelmaking waste heat as claimed in claim 1, wherein the backwater after heat exchange in said absorption refrigerator returns to the steelmaking system through a pipeline.

4. The inverter cooling system apparatus based on steelmaking waste heat as claimed in claim 1, wherein said heat dissipation and exhaust means is communicated with the outside through an exhaust pipe provided with a non-return valve.

5. The converter cooling system apparatus based on steelmaking waste heat as claimed in claim 1, wherein said converter cabinet is provided with at least 2.

6. A control method of a converter cooling system apparatus based on steelmaking heat as claimed in any one of claims 1 to 5, characterized in that said control method comprises:

starting a steelmaking waste heat absorption type circulating refrigeration subsystem to perform refrigeration;

Acquiring a proper working temperature interval of the frequency converter, and if the frequency converter is in the proper working temperature interval, maintaining; if the cooling capacity is not matched, determining the required cooling capacity, and starting a frequency converter cooling subsystem to cool;

In the cooling or maintaining process, the temperatures of the return air and the heat exchange air are compared, if the temperature of the return air is more than or equal to the temperature of the heat exchange air, the heat exchange air blower is started to exchange heat with the cold part for cooling, and if the temperature of the return air is less than the temperature of the heat exchange air, the control valve is started to adopt the return air as a medium for cooling through heat exchange with the cold part.